This invention relates to a counterweight for an elevator, to ballast weights for this counterweight and to an elevator equipped therewith.
Conventional elevator counterweights, as shown by the appended FIGS. 1 to 3, are known to be equipped with a frame 1 comprising two vertical U-shaped posts 3 parallel and opposed to each other and connected to each other by at least one upper cross-beam 5 and one lower cross-beam 7. The wings 9 of the vertical posts, as best seen in FIG. 3, accommodate flat ballast weights 11 forming a mass, piled up on each other in the frame 1. The lower ballast weights are mounted into the frame by inclining them and the upper ballast weights can be inserted horizontally by first inserting an end of the ballast weight into one of the posts 3 and pushing the other end into the other post 3 through a lateral upper cutout 13 provided at the end of that post, then descending the ballast weight between the posts onto the piled-up ballast weights. The ballast weights are assembled up to the top of the frame 1. Finally, the cutout 13 is closed by a stopper (not represented). Such a cutout 13 in one of the posts reduces the strength of the counterweight frame and requires thicker posts, therefore a higher manufacturing cost.
In addition, if no cutout is provided on the post in a counterweight as illustrated by FIG. 2, the ballast weights 11 must be mounted inclined between the posts 3 of the frame. Thus a considerable ballast weight loading space is lost in the upper portion, which can force to lengthen the counterweight frame in order to meet a maximum mass requirement for the counterweight.
In addition, modern elevators without a machine room and with smaller shaft top and bottom spaces require shorter counterweights with the same or even a greater weight.